Apparatus and method for radio transmission and reception



7 July 25, 1933. J 5, STQNE 1,919,309-

APPARATUS AND METHOD FOR RADIO TRANSMISSION AND RECEPTION Filed May 6,1930 2 Sheets-Sheet l ATTORNEY J. S. STONE July 25, 1933.

APPARATUS AND METHOD FOR RADIO TRANSMISSION AND RECEPTION Filed May 6,1930 2 Sheets-Sheet 2 I I i Fnfymd INVENTOR I (Egg/05mm $150M ATTORNEYis to send radio signals on several different;

Patented July 25,- 1933 U IT -e was JOHN STONE APPARATUS AND METHOD nonmm; TnA'iisMrssIon ANn nnonr'rion Application filed May 6, 1930. Serialnaasaaaa The principal object of my invention is to provide new andimproved apparatus and a corresponding method for the propagation andreceptionof radio signals without impairment by fading orsimilarellects. ;Another object of my invention is to provide fortransmitting and .receivingradio signals on several differentfrequencies with a minimum of interference to other receiving stationsthan the one for which the signals are intended. Still another object ofmy invention frequencies so related in phase and in fre quency intervalthat interference with nonintended receiving stations is a minimum.

These and other objects of my invention will i be readily perceived onconsideration of a limited number of examples of practice according tothe invention, which I have cho-c sen to present in thefollowingspecification. It will be understood that this disclosure'hasreference to these particular examples of the invention and that itsscope will be indicated in the appended claims. i Referring to thedrawings, Fig. 1 is adim grammatic elevation of a multiple antennatransmitting system. Fig. 2 is a diagrammatic elevation of acorresponding receiving system. F ig. 3'is a diagrammatic elevation of amultiple antenna transmitting -system with sequential oppositemodulation in the series of antennas. Fig. 4 is a diagrammatic elevationof a receiving; system adapted for cooperation with the transmittingsysteinof Fig. 3, Fig. 5 is, a diagram indicating the freq'uenciesthatmaybe employed in connection with the system of Figs. 3 andi, Fig. (Sis a similar diagram with asomewhat different set offrequencies, Fig. 7 is a transmitting.

station for operation according-to the frequency plan indlcated in Fig.6, and Fig 8 1s a corresponding receiving station.

As a reason for the obj ectionahle phenomenon of fading 1I1 ILd1O16C8pt1OI1, it is the common opinion that th s is due tothe arrival atthe receiving station of different wave fronts from the transmittingstation "that havecome over" different paths and that .ing station aninterference pattern on'the a rive. at the receiving station in oppositeor nearly opposite phase, The dlfiieren-ceof the two paths is ascribedto the Heaviside layer with the view that one Wave trainsufl'ers morereflections betweenthis layer and the earthssurface than the other. Suchbeing the case, there will be} at and near thereceivground; inonezonerthe waves will interfere and produce null reception .ini'aneighboring zone the waves will be in phase and willproduoe asubstantial efiect. Due to changing conditionsin the Heaviside layer,and other changes, this-interferencepattern shifts in time giving thewell-known phenomenon of intermittent fading. V v

Obviously this shifting pattern dependson the frequency -and anentirelydifl'erent pattern will be produced bywavesof' a differentfrequency, Itis a principle employed in the present connection totransmit on several dii'? ferent frequencies; simultaneously so thateven though there may interference at the re:

ceiving station for one of thosefrequencies,

the chance of interference for of them will I be exceedingly small.

Figure 1 represents a transmitting station according to the principlethat has just been stated. I The. respective radiating antennas .areenergized at diflerent frequencies but their cnr'rentsare-all modulatedfromthe one transmltter T. The corresponding receiving MEN (IFYF'IQFEs'roNE, or'snn DIEGO, oALIFo'n-iIIA assrenonro Am cmimmrnqm ANDTELEGRAPH COMPANY, A oonronzi'rion on NEW YORK station is shown in Thereceived currents in ts antennas are of diflerent frequency but are allreduced to audio frequency currents which flow in the single receiver R.

multiple circuits to Oi' jobjection to thitlfansllnitfillgiafid :re;

ceiving stations of Figs. 1 and Qisthatthey,

employ 'a considerable range of frequencies which may extend so far asto cause interference with the receiving station or stations of systemsthat are desired tobe- -keptindepend- I Q Referring to Fig-Q3, thisshows. a'fse t of transmitting antennas energized in frequen case,unlike Fig. 1-,;the modulation is opporsite going from each antennatothenext :of the series thatis, when thepower on the first is increasing,it-is decreasing on the sec 'eof . 5 cies which grade from left toright.this the fourth, and so on.

0nd, increasing on the third, decreasing on Adapted for cooperation withthe transmitting system is the receiving system shown in Fig. 4, where adifferential telephone receiver R is employed connected in'one sensewith one set of alternate receiving antennas 1, 3 and 5, and in theopposite sense with the remaining alternate set of receiving antennas 2,4: and 6. This connection compensates for the opposite sense in whichmodulation of the corresponding two groups-of'antennas at thetransniitter'takes place, so: that the ultimate receiver in Fig. 4responds to the arithmetical sum ofthe audio frequency responses of allthe demodulators just as in the case of the system illustrated in Figs.1 and 2.

The disturbance of nearby-stations by the system of band or groupfrequency transmitters of 3 is decidedly less than that which wouldresult from-the band 'or group trans it has been assumed that thefrequencies were graded nearly evenly along the series of antennas atthe transmitting station and lil:e-

wise at the receiving station. That is, suppose the evenlygradedfrequencies heretofore assumed have been It will be seen that this is anarithmetical progression. Now instead let tlie'frequencies be I V I V In+cZ a", TH-CZ-l-(Z, -a+3da3, 1+ 361+ a, etc. where d is small comparedwith 0?. These frequencies will lie along a frequency scale as indicatedin Fig. 5. Assume that these frequencies are imposed on the respectiveantennas of the transmitting array of Fig. ,3. Thus two frequenciesquite close together are oppositely modulatedfand tie reduction ofinterference is substantially greater than when the frequeucieswereevenly graded as assumedfat an earlier sta e of this discussion.

In one aspect my invention involves radio I signaling on two or morechannels so as to duced secure privacy and freedom from interference,and otheradvantages. I I v The crosstali produced in a single channel 13line of frequency a bythe two-channel line whose frequencies are n, cZand 7t"+(l' is considerabl less than that which would occurbetweentwo'one-channel lines whose respective frequencies were at: and it; this isin accordance with'the foregoing uisclosure.

But'it can be shown that the cross-talk proinfa single-channellino offrequency a by what Ica'll a concentricchannelline whose frequenciesaren'f -cZ, a, andn +d is decidedly less than in thecase mentioned centricchannel receivers.

above. This principle is embodied in a system whose construction willreadily be apparent in Fig; 6 as compared with Fig. 5. In this diagram,as in Fig. 5, the frequencies used as channels of the radiotrausmissio-n'are indicated by the letters above t e horizontal linewhich represents the frequency range, but the relative amplitudesorintensities of the radiations transmitted on these channels areindicated by the numerals 1, 2,1 below the frequency range line, the reitive phases of the modulation of the radiations transmitted on thechannels is indicated below the range line by the signs t i. The threechannels of each one of thegroups of Fig. 6 are what I calla concentricchannel line and the types of transmitters and receivers used intransmitting and receiving in such a system areindicated respectively inFigs. 7 and 8. H I I 1 In Fig. 7 the four antennas shown are ener-'gized by the four equalisources 1, 2, 3,and liese sources are'offrequencies n+pd d,

i n-tpcl, "wt-pal, and a-tpcfit d respectively.

antennas radiate waves of equal intensity. or amplitude. ciated with thefour sources 1, 2,3 and e, that sources 1 and 4- are modulated in unisonand sources 2 and. 3 are also modulated in unison, but in opposite phaseor sense to that of sources 1 and 4. I

In Fig. 8 the four antennas are coiinect-' ed to four equal detectors 1,2, 3, and 4,

the antennas being respect vely attuned to frequencies -n+pcZcZ, ntpd,.n-l-prl n-i-pcZ-lwl. I The adjustments-are such that the, four antennaswith their associated detectors are equally receptive.

detectors 2 and 3 act upon it in'the opposite sense from detectors 1 and:4. I

In making use of such concentric channel transmitters and receivers inthe scheme of.

ne adjustments are such that the four L Thecommon' differential receiverIt is so associated'with The modulator T is so asso i Fig. 6, a numberofv such transmitters are mon modulator tahingthe place of theindividual modulators of'the concentric channel transmitters, and singlecommon differential ultimate receiver akingthe A I of the individualdifferential rece vers of the cons Iclaim: 1. The method of employing aplur of wavefrequenc es in, radio transmits. on

which consists in them according to 'Y the numbers, 11+ (1 d, a (Z d", a-F 3d (1, 7

wave frequencies in radio transmission which consists in grading themin'systematic progression in frequency and modulating them oppositely insuccession along this sequence.

3. The method of employing at least'three wave frequencies in radiotransmission with reduction of interference therefrom which consists ingrading thefrequencies and modulating and demodulating them oppositelyin succession along the graded sequence.

4. A plurality of antennas to the number of at least three, and means toenergize them with respective frequencies at intervals alternately smalland great,and to modulate them oppositely in sequence along thefrequency scale. 1 a 1 5. A plurality of antennas to the number of atleast three, and means to energize them with frequencies differingregularly'in se-.

quence along the frequency scale, and to modulate them oppositely insequence along this scale.

6. The method of signaling which consists in transmitting the signals onat'least three different frequency bands with phase reversal ofmodulation in the'bands of one of the two sets of alternate bands takenalong the frequency scale, and combining the received wave effects atthe-receiving station with phase reversal in the same bands in whichthere was phase reversal at the transmitting station so thatthesereceived wave effects cooperate to reproduce the signals at thereceiving station but neutralize each other in respect of interference.I

7. The method of signaling which consists in transmitting the signals onat least three different equally spaced frequency bands with phasereversal of modulation in the bandsof one of the two sets of alternatebands taken along the frequency scale, and combining the received waveeffects at the receiving station with phase reversalthere in the samehands as at the transmitting station so that the effects in all thesebands cooperate at the receiving station to produce signalsbutneutralize each other in respect to interference.

8. The method of signaling which consists in transmitting the signals onthree different equally spaced and juxtaposed frequency bands with phasereversal. of modulation in one of the two sets of bands of which one setis the extreme bands andthe otherset is the intermediate band, andcombining'the received wave effects at the receiving station with phasereversal there in the same band or hands as at the transmitting stationso that the received effects cooperate to produce si nals but neutralizeeach other in respect to interference.

9. The method of signaling which consists in transmitting the signals onthree different frequencies, modulating the'extreme frequencies inopposite sense to the intermediate frequency and combining the effectsof the of interference.

three frequencies at the receiver oppositely in the same way so thatthey cooperate to produce signals, but neutralize each other theycooperate to produce signals, but neutralize each other in respect ofinterference.

v11. The method of signaling which consists in transmitting the signalson three different equallyspaced and juxtaposed frequenc es, modulatingthe extreme frequencies in opposite sense to the intermediate frequencyand combining the effectsof the three frequencies at the receiveroppositely in the same way so that they cooperate to produce otherin'respect signals, but neutralize each 12. The method of signalingwhich consists in transmitting the signals on three different equallyspaced frequencies, with the intermediate frequency at twice theintensity of the extreme frequencies, modulating the extreme frequenciesin the opposite sense to the intermediate frequency and combining theeff-ectsof the three frequencies at the receiver oppositely in the sameway so that they a cooperate to produce signals, but neutralize eachother in'r'espect of interference.

13. The method of signaling which conferentequally spaced and"juxtaposed frethe opposite sense to the intermediate fre quency andcombiningthe effectsof the three I sists in transmitting the signals onthree diffrequencies at the receiver oppositely in the same way so thatthey-cooperate to produce signals, but neutralize each other in respectof interference. 1

1%. The method of signaling which consists in transmitting the signalson three different and juxtaposed frequencies, with the intermediatefrequency at twice the intensity of the extreme frequencies, modulatingthe extreme frequencies in'the opposite'sense to the intermedlatefrequency and combin ng the effects of the three frequencies at thereceiver oppositely in the same so that they cooperate to producesignals, butneutralize each other in respectof interference;

15. In a transmitter, three antennas, means for energizing them withrespective different frequencies, and means for modulating the extremefrequencies in the same sense and the intermediate frequency in theopposite sense. v

16. In a transmitter, three antennas, means cut equally spacedfrequencies, and means for modulating the extreme frequencies in thesame sense and the intermediate frequency in the opposite sens 17. Intransmitter, threeantennas, means for-energizing them with respectivedifierent equally spaced juxtaposed frequencies, and mean; formodulating the extreme frequencies in the same sense and theintermediate frequency in the opposite sense.

18. In a transmitter, four equal antennas,

means for energizing we of them each with frequenm in the opposite senseto that with which the extreme frequencies are modulated. r

' 20. In a trans er, four equal antennas, means for o ng two of 1.16111each with oneof the extrei; e frequencies of a group of three equallyspaced and juxt posed frequencies and the other two ante-mas with theremainng frequency, means for modulat 16Clltt8 frequency the opg iosites t with which the extreme frequencies modulated.

21. In a trans tter, four equal antennas, means for ener ring two ofthem each with iextreme frequencies of group uencies and other two an,-the remaining frequency, the such as to equally All.

tennas v I means he]. g energize the four ant ms and means-for i theinirequency in the opposite sense to that with which the extremefrequencies are modulated,

22. in a transmitter, four equal antennas, means for ener izing two ofthem each with one of the on no frequencies of a group of three equa yspacco frequencis and the other two ai nnas with the remainingfrequency, the energizing means being such as to e ually the fourantennas and me as for modulating the intermediate fre- LLC qi ncy inthe opposite sense to that with ich the extreme frequencies aremodulated.

23. In transmitter, four equal antennas, means for energiz two of tncmeach with one of rcme frequencies of a group of three equay spaced andjuxtaposed frequencies d the other two antennas with throman frequency,the energising means b such to equally energize the four ant s means formodulating the intermediate frequency in the opposite sense quencyoutputs, a telephone receiver common to the four component receivers,the components of extreme frequency being connected to the telephonereceiver oppositely to the components of intermediate frequency,

whereby in the reception of correspondingly opposite frequency bands theaudio frequency outputs of the several component receivers are caused tocooperate in actuating the telephone receiver in the production ofsignals, but neutralize each other in respect of interference. 1

25. In a radio receiver, four component receivers, two of which areattuned each to one of the extreme frequency bands of a group of threeequally spaced frequency bands, the other two attuned to theremainfrequency band of the group, said component receivers beingadapted to produce respective audio frequency outputs, a telephonereceiver common to the four compo- I nent receivers, the components'ofextreme frequency being connected to the telephone receiver oppositelyto the components of intermediate frequency, whereby in the reception ofcorrespondingly opposite frequency bands the audio frequency outputs ofthe several component receivers are caused to cooperate in actuating thetelephone receiver in the production of signals, but neutralize eachother in respect of interference.

26. In a radio receiver, four component receivers, two of which areattuned each to one of the extreme frequency bands of a group of threeequally spaced and juxtaposed frequency bands, the other two attuned tothe remaining frequency band of the group, said component receiversbeing adapted to produce respective audio frequency outputs, a telephonereceiver common to the four component receivers, the components ofextreme] frequency being connected to the telephone receiver oppositelyto the components of 1ntermediate frequency, whereby 1n the reception ofcorrespondingly opposite frequency bands the audio frequencyoutputs ofthe several component receivers are caused to cooperate in actuating thetelephone receiver in the production of signals, but neutralize eachother in respect of interference.

27. In a radio receiver, four component receivers of equal receptivity,two of which are attuned each to one of the extreme frequency bands of agroup of three frequency ponent receivers being adapted toyproduoerespective audio frequencyoutputs, a tele 5 frequency being connectedptothe telephone receiver oppositely to the components of intermediatefre'quencypwh'erebyin the reception of correspondingly oppositefrequency bands the audio frequency outputs of the several componentreceivers are'caused to cooperate in actuating the telephone receiver inthe production of signals, but neutralize each other in respect ofinterference. 1

28. In a radio receiver, four component receivers of equal receptivity,.two of which are attuned each to one of the extreme fre quency bands ofa group of three equally spaced frequency'bands, the other two attunedto the remaining frequency. band of the group, saidcomponent; receiversbeing adapted to produce respective audio fre quency outputs, atelephone -.receiver common to the four component receivers, thecomponents of extreme frequency being connected to the telephonereceiver oppositelyto the components of intermediate frequency,.

whereby in the reception of correspondingly opposite frequency bands theaudio frequency outputs of theseveral component receivers 30 are causedto cooperate in actuatingithe tele-.

phone receiver in the production of signals,

but neutralize each other in respect of interference. V 1 V 29. In aradio receiver, four component receivers of equal receptivity, two ofwhich are attuned each to one of the extreme frequency bands of a groupof three equally spaced and juxtaposed frequency bands,the other twoattuned to the remaining frequency band of the group, said componentreceivers being adapted to produce respective audiofrequency outputs, atelephone receiver comcomponents of extreme frequency being con nectedto the telephone receiver opposltely to the components of intermediatefrequency, whereby in the reception of correspond ngly oppositefrequency bands the audio frequency outputs of the several componentreceivers 0 are caused to cooperate in actuating the tele-.

phone receiver in the production of signals, but neutralize each otherin respect of inter ference. V a

30'. Ina radio receiver, three component receivers, two of which areattuned to the extreme frequency bands of a group "of three frequencybands, the other component receiver being attuned to therema ining frequency band of the group, said component receivers being adaptedtoproduce respective audio frequency outputs, a telephone receiver commonto the three component receivers, the components 'of extreme frequencybeing connected to the telephone receiver oppositelyto the components ofintermediate frequency,

whereby in the reception ofcorrespondingly opposite frequency bands the.audio frequency outputs of the threecomponentfreceivers are caused tocooperate ,in' actuatin'gthe telephone receiverin the production ofsignals, but

neutralize each other in'respect of :interfer-J ence,

receiversftwo of which are attuned: to the extreme frequency bands ofagroup of three 31. Ina radio receiver, three component componentreceivors'being'adapted to pro:

duce respective audio frequency outputs,a

telephone receiver common tothe threecomponentreceivers, the-componentsof extreme frequency being connected to thei telephone receiver.oppositely to the components offintermediate frequency, whereby mulerecep tion of correspondingly opposite'ffrequency bands theaudioifrequency outputs of three component receivers are caused tocooperate n actuating the telephone receiver in the pro duotionofsignals,'but neutralize each other jv in respect of interference.

32. In a radio receiver, three component receivers, two of which areattuned to the extreme frequency bands of a group of three equallyspaced and juxtaposed frequency bands, the other component receiverbeing atgroup,said. component receivers being adapted to producerespective audio frequency outn puts, a telephone receiver common to thethree of intermediate frequency, whereby in the reception ofcorrespondingly opposite frequency bands the audio frequency outputs ofthree component receivers are caused to coopmon to the four componentIBCBIVQIS, the,

tuned tofthe remaining frequency'band of the erate in actuating thetelephone receiver in the production of signals, but neutralizeeachother in respect of interference.

33. In a radioreceiver, three component receivers, two of which are ofequal recep tivity and are attuned-respectively to the extreme frequencybands of a group of three a frequency bands, thethird component receiver'having a receptivity double thatof either of the other componentreceivers and'being attuned to the remaining frequency band,

said component receivers being adapted to produce respective-audiofrequency outputs," 'a telephone receiver common to the three,

component receivers, the components of extreniefrequencybeing connectedto the telephone receiver oppositely to the components of intermediatefrequency, whereby in the reception of correspondingly oppositefreproduction of signals, but neutralize each other in respect'ofinterference. v q

84. In a IflllOI'GCBlVBI', three component receivers, two of which areof equal receptivity and are attuned respectively to the extremefrequency bands of a group of'three equally spaced frequency loandsthevthird component receiver having a receptivity double that of eitherof the other component receivers and being attuned to the remainingfrequency band, said component receivers being adapted to producerespective audio frequency outputs, a telephone receiver common to thethree component receivers, the components o-fex treme frequency being'connected to thetelephone receiver oppositely to the componentsofintermediate frequency,

"whereby in the reception of correspondingly opposite frequency bandsthe audio frequency outputs of the several component recelvers arecaused to cooperate on the tele-' phone receiver in the production ofsignals,

but neutralize each other in respect of inter ference.

' 35. In a radio receiver three component receivers, two of Wh1ch areofequal receptivity and are attuned respectively to the extreme frequencybands of a group of three equally spaced and juxtaposed frequency bands,the third component receiver having a receptivity double thato f eitherof the other component receivers and being attuned ponentreceivers'being. adapted to produce respective audio frequency outputs,a telephone receiver common to the'three con1- to the remainingfrequency band, said c'omponent receivers, the components of extremeduction of signals, but neutralize each other in respect ofinterference.

JOHN STONE STO E."

